Valve silencer



Jan. 13, 1948. J. H. BRADSHAW VALVE SILENCER Filed Nov. 26, 1945 H firadsizaue I Patented Jan. 13, 1948 Nl'l'D STATES PATENT OFFICE VALVE SILENCER Jess H. Bradshaw, San Jose, Calif.

Application November 26, 1945, Serial No. 630,852

1 Claim. 1

The present invention relates particularly to the overhead valve construction of internal combustion engines.

It is one object of the present invention to provide means for eliminating all tappet noises so common to engines of the character mentioned, and prevent valves from burning which occurs when the valves do not have the proper clearance, and also to improve the motor performance generally.

It is also an object of the invention to provide a device of the character indicated that will be simple and economical in construction, quickly and easily installed in an engine, that consists of few parts, is strong and durable, and highly efficient in its practical application.

In the drawing:

Figure 1 is a longitudinal section through the center of a device embodying my invention.

Figure 2 is a sectional view through the device taken on line 22 on Figure 1.

Figure 3 is a sectional view through the device taken on line 3--3 on Figure 1.

Figure 4 is a sectional view through the device taken on line 4-4 on Figure 1.

Referring now more particularly to the drawing, I show at i a cylinder which seats in the end of the push-rod la not shown and which has a socket or recess 2 formed in the center of its bottom to form a seat for a spring element 3.

At 4 is shown a piston operating in the cylinder 1, replacing the rocker arm adjusting screw and locks with the original lock nut.

The piston 41 has an oil pocket ring groove 5 formed therein and the piston 4 and cylinder I are held in operative relation to each other by means of a lock pin 5 in the cylinder engaging an annular groove 1 in the piston.

An oil feed passage 8 is formed axially in the piston 4 to extend from its lower end upwardly a distance to the level of the groove 5 and is connected to said groove by laterally extending conduits 9.

A check valve i0 is seated in the passage 8 as shown and compression escape vents ll lead from the lower end of piston 4 to a point in the passage 8 above the check valve Ill. The bottom end of the piston 4 is bevelled as at l2 at a thirty degree angle to the horizontal to correspond with a similarly angled seat [3 on the cylinder l.

Assuming that the device is installed as described and filled with oil, it is adjusted by bearing down on the adjusting screw end of the rocker lb arm set with the desired thickness gauge to secure clearance at all motor temperatures. The oil keeps the valve continuously in contact with the rocker arm and insures the metal to metal contact. No special means or reservoir is required to supply the device with oil since the very slight leakage of oil that works down over the end of the rocker arm is amply suificient for that purpose.

In this manner more valve clearance is obtained, and at the same time secures greater power and avoids noisy valves and burning of the valves and improves motor performance in general. When the piston is pushed downwardly by the rocker arm it actuates the push rod downwardly through the medium of the oil cushion, the check valve 10 being closed the excess oil passing upwardly through conduits H to the passage 8 rearwardly of the check valve which permits the oil to flow downwardly again as the piston is raised by spring 3.

It is to be understood, of course, that while I have shown and described but one specific embodiment of the invention, changes and modifications may be made within the scope of the appended claim.

I claim:

A device of the character described comprising, a rocker arm, a piston member externally threaded at one end to screw through the rocker arm of the valve actuating mechanism of an engine and replace the standard adjusting screw and providing a piston on its other end, said piston end having an oil collecting groove encircling the same a distance from its free end and a passage connecting said groove with said free end, a valve controlling said passage, the said free end of said piston having a bevelled edge and one or more vents leading from said bevelled edge to said passage rearwardly of the valve, a cylinder slidably encompassing the piston to engage a push rod and provided with a bevelled seat in opposed relation to and corresponding with the bevelled end of the piston, and having a recess formed therein in opposed relation to the valve, resilient means inserted in said recess between the piston and cylinder, and means operable to limit the outward movement of the cylinder relative to the piston.

JESS H. BRADSHAW.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,062,580 Bollee May 27, 1913 1,144,987 Adams et al. July 6, 1915 1,336,447 Suffa Apr. 13, 1920 1,583,335 Borschel May 4. 1926 1,798,938 Hallett Mar. 31. 1931 1,977,736 Mueller Oct. 23, 1934 1,977,778 Rice Oct. 23. 1934 2,090,795 Johnson Aug. 24, 1937 2,109,459 Best Mar. 1, 1938 

